Effect of different storage media on the microhardness and wear resistance of resin-matrix ceramics

This in vitro study evaluated the microhardness and two-body wear of various computer-assisted design and computer-assisted manufacturing (CAD/CAM) resin-matrix ceramic materials stored in different storage media. For each material (Paradigm MZ100, Lava Ultimate, Vita Enamic, and Cerasmart), 40 disk-shaped specimens (8 mm diameter × 3 mm thickness) were prepared and divided into four subgroups (n = 10) according to storage material (artificial saliva, distilled water, 0.02 mol/L citric acid, 3:1 ethanol/water). Following storage at 37°C for 7 days, microhardness was measured with a Knoop test, and wear was measured using a 3D scanner and surface analysis program before and after loading on a chewing simulator (200 000 cycles). Wear values of Vita Enamic were lower in comparison to the other materials tested (P < 0.001). Storage media were found to have a significant effect on material microhardness (P < 0.001), but not on wear (P = 0.820).     

陶瓷料浆体系的稳定与分散

介绍陶瓷浆料体系的稳定与分散机制，并简要介绍国内对各种体系陶瓷料浆的胶体行为的研究情况。     

高炉用热模压炭砖

分析了高炉炭砖的损毁机理，对用热模压工艺制备的炭砖进行了研究。研究表明，采用热模压工艺制备的炭砖气孔为闭合微孔，选择适当的加压曲线和电流密度等工艺参数能制备出高导热、低渗透率、抗碱侵蚀性良开的炭砖。     

220 kV变电站的CSC2000综合自动化系统

以220 kV新塘变电站为实例,分别从保护、当地监控、远动主站、工程师站及录波系统、网络构架、系统性能6个方面介绍了改进的CSC2000综合自动化系统,进一步强调了综合自动化系统中设备按照间隔分布、保护功能相对独立的设计思想,以及该系统模块化的网络结构和网络通信特点.     

面向多级调度管理的融合型搜索引擎

云计算、物联网、社交网络等新兴服务模式的产生与发展,使得数据转变为一种基础资源,面向数据管理和取用的信息检索技术的重要性不断提高。结合调度管理业务的典型搜索需求,文中将信息服务模式的技术特征应用于调度管理领域,提出一种面向大电网多级调度管理一体化的融合型搜索引擎设计方法。该方法通过对不同类型数据的搜索集成,实现了分布式环境下的异构数据资源整合。针对所述算法进行了实验仿真和原型验证,对搜索算法进行了可行性评估和应用展望。     

电网调度省地一体化试点工程关键技术方案

为适应电网智能化发展的进一步要求,省地电力调度控制中心(简称省地调)基于全景信息进行电网一体化运行和统一协调控制成为迫在眉睫的需求。文中针对电网模型、采集数据、功能应用等方面对电网调度省地一体化关键技术开展研究,实现省地调之间电网模型、图形等信息能够动态交互和按需共享,实时数据、历史数据、故障信息等信息能够动态交互、按需引用和校核互备,并探索实现若干省地一体化典型应用。该研究课题也是智能电网调度技术支持系统在江苏试点工程建设的重点内容。     

基于两阶段鲁棒区间优化的风储联合运行调度模型

为了全面和准确地考虑风电出力的不确定性和消纳能力,并兼顾系统运行的经济性和可靠性,通过在风电不确定区间可优化的鲁棒区间经济调度模型中引入常规机组和储能系统运行状态的离散决策变量,建立风储联合运行的双层鲁棒区间机组组合模型。针对连续变量和离散变量间存在耦合关系,导致计算过程中对偶转换失效而使模型难以求解的问题,提出基于Benders分解算法的两阶段迭代求解策略。仿真分析表明,所提模型在确定风储联合运行方式时,能更全面地考虑风电不确定性及消纳能力对系统运行经济性和可靠性的影响。     

协调经济性及电压稳定性的受端系统紧急负荷控制优化方法

特高压直流逆变站闭锁后,应在确保受端系统安全稳定的前提下尽量减小紧急控制的经济代价,同时,为了使逆变器尽快恢复正常运行,控制后的系统还需要提供足够的无功支撑,为此提出了一种协调经济性及电压稳定性的受端系统紧急负荷控制优化方法。首先,讨论了事故发生后受端系统的动态响应,提出根据电压薄弱性指标识别受端系统的若干电压薄弱节点,将其电压跌落量的平方和作为电压稳定性指标;然后,计算控制方案对应的负荷损失及事故罚款,将两者之和作为经济指标。为克服分段优化问题的求解困难,首先将分段的事故罚款曲线进行了近似光滑处理;然后,在考虑频率、电压及潮流等约束条件的基础上,以经济性、电压稳定性指标的加权和最小为目标,构建紧急负荷控制优化问题的数学模型,并应用原对偶内点法快速求解;最后,以含高压直流输电的IEEE 10机39节点系统为例,对算法进行了验证。结果表明,协调经济性及电压稳定性的优化控制可在不增加经济代价的前提下,改善控制后系统的电压稳定性,有助于逆变站恢复运行。     

A miniature concentrating photovoltaic and thermal system

A novel miniature concentrating PV (MCPV) system is presented and analyzed. The system is producing both electrical and thermal energy, which is supplied to a nearby consumer. In contrast to PV/thermal (PV/T) flat collectors, the heat from an MCPV collector is not limited to low-temperature applications. The work reported here refers to the evaluation and preliminary design of the MCPV approach. The heat transport system, the electric and thermal performance, the manufacturing cost, and the resulting cost of energy in case of domestic water heating have been analyzed. The results show that the new approach has promising prospects.     

Dynamics of attentional selection under conflict: Toward a rational Bayesian account.

The brain exhibits remarkable facility in exerting attentional control in most circumstances, but it also suffers apparent limitations in others. The authors’ goal is to construct a rational account for why attentional control appears suboptimal under conditions of conflict and what this implies about the underlying computational principles. The formal framework used is based on Bayesian probability theory, which provides a convenient language for delineating the rationale and dynamics of attentional selection. The authors illustrate these issues with the Eriksen flanker task, a classical paradigm that explores the effects of competing sensory inputs on response tendencies. The authors show how 2 distinctly formulated models, based on compatibility bias and spatial uncertainty principles, can account for the behavioral data. They also suggest novel experiments that may differentiate these models. In addition, they elaborate a simplified model that approximates optimal computation and may map more directly onto the underlying neural machinery. This approximate model uses conflict monitoring, putatively mediated by the anterior cingulate cortex, as a proxy for compatibility representation. The authors also consider how this conflict information might be disseminated and used to control processing. (PsycINFO Database Record (c) 2010 APA, all rights reserved)